Table Of Contents

DAQmx - Data Acquisition Nodes

Use the DAQmx - Data Acquisition Nodes with NI-DAQmx hardware devices to develop instrumentation, acquisition, and control applications. Refer to your readme file for a complete listing of devices that NI-DAQmx supports.

Device Configuration

Immediately aborts all active tasks associated with a device, disconnects any routes, and returns the device to an initialized state. Aborting a task immediately terminates the currently active operation, such as a read or a write. Aborting a task puts the task into an unstable, but recoverable state. To recover the task, use DAQmx Start Task to restart the task, or use DAQmx Stop Task to reset the task without starting it.

Controls the watchdog timer task according to the action you specify. This node does not program the watchdog timer on a real-time controller. Use the Real-Time Watchdog to program the watchdog timer on a real-time controller.

Task Config/Control

Creates a task and adds virtual channels to that task if you specify them in the global virtual channels input. If you specify a task to copy, this node duplicates the configuration of the specified task in the newly created task before it adds any additional global virtual channels.

Export

Routes a control signal to the terminal you specify. The output terminal can reside on the device that generates the control signal or on a different device. You can use this node to share clocks and triggers among multiple tasks and devices. The routes this node creates are task-based routes.

Contains a Register for Events function, an Event structure, and a DAQmx Task Name constant. You must register the DAQmx event you want to use and configure the Event structure to handle that event. You must also use the DAQmx Task Name constant to select or create a task. You can use a DAQmx Task Name control in place of the constant.

Calibration

Measures the onboard reference voltage of the device, and adjusts the self-calibration constants, to account for any errors caused by short-term fluctuations in the operating environment. When you self-calibrate a device, no external signal connections are necessary.

Adjusts the internal and external calibration constants for an NI 4220 device. This device requires reference signals of 0.0 volts at gains of 1, 15, 20, and 310 on a particular channel, in order to perform an offset calibration for that channel. If you do not manually supply those reference signals, the device measures them internally with sample and hold circuitry enabled.

Scale Setup

Computes a set of coefficients for a polynomial that approximates the inverse of the polynomial with the coefficients you specify with the coefficients input. This VI generates a table of x versus y values over the range of x. This VI then finds a polynomial fit, using the least squares method to compute a polynomial that computes x when given a value for y.